Improved error probability evaluation methods for direct detection optical communication systems

The problem of average error probability evaluation for direct detection binary optical communications in the presence of avalanche gain, intersymbol interference, and colored additive Gaussian noise is considered. Tight new upper and lower bounds, together with a modified Gaussian quadrature rule based on approximate moments, are derived and evaluated. The bounds are found to be much tighter than the Chernoff bound though only slightly more complex to evaluate, and can be used as approximations to the error probability in most cases of practical interest. Taken together the new bounds and the modified Gaussian quadrature rule form a comprehensive set of performance evaluation tools offering a judicious balance between complexity and accuracy.